Earth Notes

4:00 am

Wed July 25, 2012

Earth Notes: Arizona Mountain Tree Frog

In 1986, after a statewide vote by thousands of school children, the Arizona Tree Frog became Arizona’s official state amphibian. Beating out better-known rivals like the spadefoot toad by a wide margin, this small and seldom-seen frog might seem an unlikely candidate for top spot. But it makes sense when you realize how much they love to climb.

Rarely more than two inches long, with smooth green skin and a dark stripe running from eye to rear, these amphibians live mostly above 5,000 feet in the forests of central-northern Arizona, close to streams and wet meadows.

For much of the year Arizona Tree Frogs are dormant, becoming active only with the onset of the summer rainy season. In July or August, after the first couple rainstorms, they’re out looking for mates. And that’s when they put their tree climbing abilities to use. Helped by disk-like pads at the tips of their toes, males ascend trees and start calling.

These diminutive climbers can be tough to spot, but if you’re out in the forest on a humid monsoonal afternoon and hear intermittent duck-like quacks from the trees—that may well be them.

If you stick around as darkness falls, the calls may gradually near the ground. That’s because on the right night the amorous amphibians leave their perches to crowd into small, temporary pools. They’ll breed there, and about 11 weeks later the resulting tadpoles will morph into next summer’s generation of tiny, amphibious tree climbers.